Publications
Filter Total Items: 167
Spatial and temporal patterns of dissolved organic matter quantity and quality in the Mississippi River Basin, 1997–2013
Recent studies have found insignificant or decreasing trends in time-series dissolved organic carbon (DOC) datasets, questioning the assumption that long-term DOC concentrations in surface waters are increasing in response to anthropogenic forcing, including climate change, land use, and atmospheric acid deposition. We used the weighted regressions on time, discharge, and season (WRTDS) model to e
Authors
Sarah M. Stackpoole, Edward G. Stets, David W. Clow, Douglas A. Burns, George R. Aiken, Brent T. Aulenbach, Irena F. Creed, Robert M. Hirsch, Hjalmar Laudon, Brian Pellerin, Robert G. Striegl
Detecting spatial regimes in ecosystems
Research on early warning indicators has generally focused on assessing temporal transitions with limited application of these methods to detecting spatial regimes. Traditional spatial boundary detection procedures that result in ecoregion maps are typically based on ecological potential (i.e. potential vegetation), and often fail to account for ongoing changes due to stressors such as land use ch
Authors
Shana M. Sundstrom, Tarsha Eason, R. John Nelson, David G. Angeler, Chris Barichievy, Ahjond S. Garmestani, Nicholas A.J. Graham, Dean Granholm, Lance Gunderson, Melinda Knutson, Kirsty L. Nash, Trisha Spanbauer, Craig A. Stow, Craig R. Allen
Operationalizing the telecoupling framework for migratory species using the spatial subsidies approach to examine ecosystem services provided by Mexican free-tailed bats
Drivers of environmental change in one location can have profound effects on ecosystem services and human well-being in distant locations, often across international borders. The telecoupling provides a conceptual framework for describing these interactions—for example, locations can be defined as sending areas (sources of flows of ecosystem services, energy, or information) or receiving areas (re
Authors
Laura Lopez Hoffman, James E. Diffendorfer, Ruscena Widerholt, Wayne E. Thogmartin, Gary McCraken, Rodrigo Medellin, Kenneth J. Bagstad, Amy Russell, Darius J. Semmens
A trans-national monarch butterfly population model and implications for regional conservation priorities
1. The monarch has undergone considerable population declines over the past decade, and the governments of Mexico, Canada, and the United States have agreed to work together to conserve the species.2. Given limited resources, understanding where to focus conservation action is key for widespread species like monarchs. To support planning for continental-scale monarch habitat restoration, we addres
Authors
Karen Oberhauser, Ruscena Wiederholt, James E. Diffendorfer, Darius J. Semmens, Leslie Ries, Wayne E. Thogmartin, Laura Lopez-Hoffman, Brice Semmens
A framework for modeling emerging diseases to inform management
The rapid emergence and reemergence of zoonotic diseases requires the ability to rapidly evaluate and implement optimal management decisions. Actions to control or mitigate the effects of emerging pathogens are commonly delayed because of uncertainty in the estimates and the predicted outcomes of the control tactics. The development of models that describe the best-known information regarding the
Authors
Robin E. Russell, Rachel A. Katz, Katherine L. D. Richgels, Daniel P. Walsh, Evan H. Campbell Grant
Powell Center Newsletter, Volume 3, Issue 1
Newsletter for the John Wesley Powell Center for Analysis and Synthesis, covering news from most of FY2016.
Authors
Marcia McNiff
Prediction of fish and sediment mercury in streams using landscape variables and historical mining
Widespread mercury (Hg) contamination of aquatic systems in the Sierra Nevada of California, U.S., is associated with historical use to enhance gold (Au) recovery by amalgamation. In areas affected by historical Au mining operations, including the western slope of the Sierra Nevada and downstream areas in northern California, such as San Francisco Bay and the Sacramento River–San Joaquin River Del
Authors
Charles N. Alpers, Julie L. Yee, Joshua T. Ackerman, James L. Orlando, Darrell G. Slotton, Mark C. Marvin-DiPasquale
Temperature response of soil respiration largely unaltered with experimental warming
The respiratory release of carbon dioxide (CO2) from soil is a major yet poorly understood flux in the global carbon cycle. Climatic warming is hypothesized to increase rates of soil respiration, potentially fueling further increases in global temperatures. However, despite considerable scientific attention in recent decades, the overall response of soil respiration to anticipated climatic warming
Authors
Joanna C. Carey, Jianwu Tang, Pamela H. Templer, Kevin D. Kroeger, Thomas W. Crowther, Andrew J. Burton, Jeffrey S. Dukes, Bridget Emmett, Serita D. Frey, Mary A. Heskel, Lifen Jiang, Megan B. Machmuller, Jacqueline Mohan, Anne Marie Panetta, Peter B. Reich, Sabine Reinsch, Xin Wang, Steven D. Allison, Chris Bamminger, Scott D. Bridgham, Scott L. Collins, Giovanbattista de Dato, William C. Eddy, Brian J. Enquist, Marc Estiarte, John Harte, Amanda Henderson, Bart R. Johnson, Klaus Steenberg Larsen, Yiqi Luo, Sven Marhan, Jerry M. Melillo, Josep Penuelas, Laurel Pfeifer-Meister, Christian Poll, Edward B. Rastetter, Andrew B. Reinmann, Lorien L. Reynolds, Inger K. Schmidt, Gaius R. Shaver, Aaron L. Strong, Vidya Suseela, Albert Tietema
Improving spatio-temporal benefit transfers for pest control by generalist predators in cotton in the southwestern U.S.
Given rapid changes in agricultural practice, it is critical to understand how alterations in ecological, technological, and economic conditions over time and space impact ecosystem services in agroecosystems. Here, we present a benefit transfer approach to quantify cotton pest-control services provided by a generalist predator, the Mexican free-tailed bat (Tadarida brasiliensis mexicana), in the
Authors
Ruscena Wiederholt, Kenneth J. Bagstad, Gary F. McCracken, Jay E. Diffendorfer, John B. Loomis, Darius J. Semmens, Amy L. Russell, Chris Sansone, Kelsie LaSharr, Paul M. Cryan, Claudia Reynoso, Rodrigo A. Medellin, Laura Lopez-Hoffman
Comparison of mercury mass loading in streams to atmospheric deposition in watersheds of Western North America: Evidence for non-atmospheric mercury sources
Annual stream loads of mercury (Hg) and inputs of wet and dry atmospheric Hg deposition to the landscape were investigated in watersheds of the Western United States and the Canadian-Alaskan Arctic. Mercury concentration and discharge data from flow gauging stations were used to compute annual mass loads with regression models. Measured wet and modeled dry deposition were compared to annual stream
Authors
Joseph L. Domagalski, Michael S. Majewski, Charles N. Alpers, Chris S. Eckley, Collin A. Eagles-Smith, Liam N. Schenk, Susan Wherry
Mercury and methylmercury in aquatic sediment across western North America
Large-scale assessments are valuable in identifying primary factors controlling total mercury (THg) and monomethyl mercury (MeHg) concentrations, and distribution in aquatic ecosystems. Bed sediment THg and MeHg concentrations were compiled for > 16,000 samples collected from aquatic habitats throughout the West between 1965 and 2013. The influence of aquatic feature type (canals, estuaries, lakes
Authors
Jacob Fleck, Mark C. Marvin-DiPasquale, Collin A. Eagles-Smith, Joshua T. Ackerman, Michelle A. Lutz, Michael T. Tate, Charles N. Alpers, Britt D. Hall, David P. Krabbenhoft, Chris S. Eckley
By
Ecosystems Mission Area, Water Resources Mission Area, Environmental Health Program, Toxic Substances Hydrology, California Water Science Center, Forest and Rangeland Ecosystem Science Center, John Wesley Powell Center for Analysis and Synthesis, Upper Midwest Water Science Center, Mercury Research Laboratory
A synthesis of terrestrial mercury in the western United States: Spatial distribution defined by land cover and plant productivity
A synthesis of published vegetation mercury (Hg) data across 11 contiguous states in the western United States showed that aboveground biomass concentrations followed the order: leaves (26 μg kg− 1) ~ branches (26 μg kg− 1) > bark (16 μg kg− 1) > bole wood (1 μg kg− 1). No spatial trends of Hg in aboveground biomass distribution were detected, which likely is due to very sparse data coverage and d
Authors
Daniel Obrist, Christopher Pearson, Jackson Webster, Tyler J. Kane, Che-Jen Lin, George R. Aiken, Charles N. Alpers